content: /**
   * Copyright (c) 2012, Andy Janata
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without modification, are permitted
   * provided that the following conditions are met:
   * 
   * * Redistributions of source code must retain the above copyright notice, this list of conditions
   *   and the following disclaimer.
   * * Redistributions in binary form must reproduce the above copyright notice, this list of
   *   conditions and the following disclaimer in the documentation and/or other materials provided
   *   with the distribution.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
   * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package net.socialgamer.cah.handlers;
  
  import java.util.Map;
  
  import javax.servlet.http.HttpSession;
  
  import net.socialgamer.cah.Constants.AjaxRequest;
  import net.socialgamer.cah.Constants.ErrorCode;
  import net.socialgamer.cah.Constants.ReturnableData;
  import net.socialgamer.cah.Constants.SessionAttribute;
  import net.socialgamer.cah.RequestWrapper;
  import net.socialgamer.cah.data.Game;
  import net.socialgamer.cah.data.GameManager;
  import net.socialgamer.cah.data.User;
  
  
  /**
   * Handler superclass for handlers that require a game. This finds the game and makes sure it's
   * valid and specified.
   * 
   * @author Andy Janata (ajanata@socialgamer.net)
   */
  public abstract class GameHandler extends Handler {
  
    protected GameManager gameManager;
  
    public GameHandler(final GameManager gameManager) {
      this.gameManager = gameManager;
    }
  
    @Override
    public Map<ReturnableData, Object> handle(final RequestWrapper request, final HttpSession session) {
      final User user = (User) session.getAttribute(SessionAttribute.USER);
      assert (user != null);
  
      final int gameId;
  
      if (request.getParameter(AjaxRequest.GAME_ID) == null) {
        return error(ErrorCode.NO_GAME_SPECIFIED);
      }
      try {
        gameId = Integer.parseInt(request.getParameter(AjaxRequest.GAME_ID));
      } catch (final NumberFormatException nfe) {
        return error(ErrorCode.INVALID_GAME);
      }
  
      final Game game = gameManager.getGame(gameId);
      if (game == null) {
        return error(ErrorCode.INVALID_GAME);
      }
  
      assert game.getId() == gameId : "Got a game with id not what we asked for.";
  
      return handle(request, session, user, game);
    }
  
    /**
     * Handle a client request. The {@code Game} is guaranteed to be valid.
     * 
     * @param request
     *          The request data.
     * @param session
     *          The client's session.
     * @param user
     *          The client's {@code User}.
     * @param game
     *          The {@code Game} for this request.
     * @return Response data.
     */
    public abstract Map<ReturnableData, Object> handle(final RequestWrapper request,
        final HttpSession session, final User user, final Game game);
  }
  